Generally, seals are individual, and there are fewer combined seals. Let's understand the principle of combined seals?
A combination seal is a seal formed by the combination of two or more components. All components of the combined seal can be regarded as composed of two parts: the main seal and the auxiliary seal. The commonly used combination seal is a sealing structure composed of a main sealing ring and an elastic body, or a retaining ring and a guide ring. This type of seal is commonly referred to as an extrusion type seal. The main materials are rubber, polytetrafluoroethylene, polyurethane, polyoxymethylene, nylon, phenolic resin, etc.
The advantages of combined sealing are compact structure and saving installation space; Low frictional resistance.
The principle of combined sealing
By utilizing the support force of the elastic body after compression, the sealing effect between the sealing ring and the metal surface can be achieved, and compensation can be provided when the sealing ring is worn. It has excellent self sealing effect and has good sealing effect for both low and high pressures. At low pressure, the sealing effect is achieved by the pre tightening force of the elastomer; When under high pressure, the sealing effect of the hydraulic oil automatically increases as the pressure increases. Good sealing components require good structural design and material performance. The main sealing ring material has good elasticity and wear resistance, while the elastomer material has good elasticity, strong resistance to permanent deformation, and good anti extrusion ability of the retaining ring and guide ring materials.
So we need to design the structure well and choose high-quality materials, especially the elasticity and wear resistance of the main sealing ring material, so that we can make good use of the combined seal.
